1. Field of the Invention
The present invention generally relates to a connection pin handling device which selectively inserts or extracts a connection pin (hereinafter, insertion/extraction devices) and methods for selectively inserting or extracting a connection pin (hereinafter, inserting/extracting a connection pin). More particularly, the present invention relates to a connection pin insertion/extraction device and a method using the device in which an arbitrary line is connected/disconnected by inserting/extracting a connection pin into/from a matrix switch board.
Recently, demands have been increased for convenient methods for obtaining a telephone circuit by connecting/disconnecting conductor patterns at arbitrary points in the field of telephone switchboards. In one such method, which is currently dominating the field, a connector pin is inserted in a crossing point of a plurality of conductor patterns formed on a matrix switch board.
In the above method, the matrix switch board includes a plurality of conductor patterns located on both sides so as to cross over each other at the same coordinate. The connection between the conductor patterns is carried out by inserting a cross-shaped connection pin having two metallic protruding portions into a through-hole provided with a crossing point.
Also, the connection between the conductor patterns may be disconnected by extracting the connection pin inserted in the through-hole. The insertion/extraction operation of the connection pin may be automatically carried out by a robot, which is controlled by a computer, comprising a connection pin insertion/extraction device. It is necessary to accurately detect the position of the through-hole relative to the robot in order to precisely insert the connection pin in the through-hole. Thus, a position detection mechanism may necessarily be provided with the robot.
The above-mentioned connection pin insertion/extraction device may be applied to, for example, an automatic line distribution equipment which connects a switch board line with a subscriber line. In this case, two conductor patterns are used as the switch board line and the subscriber line, respectively. One of the switch board lines may be connected to one of the subscriber lines by inserting the connection pin in a through-hole formed at a crossing point of the two conductor patterns.
FIGS. 1A and 1B are diagrams showing the structure of a conventional connection pin insertion/extraction device. FIG. 1A is a diagram showing a front view of the device and FIG. 1B is a diagram showing a side view of the device. The connection pin insertion/extraction device shown in the figures may be mounted on an arm of a robot 1, which is capable of moving in the X, Y and Z directions, so that the device may be freely transferred between two matrix switch boards 2. In each of the matrix switch boards 2, a plurality of conductor patterns are formed so as to cross each other, and a corresponding through-hole is formed at a crossing point of the conductor patterns. The connection pin insertion/extraction device inserts a connection pin 3 in the through-hole formed in the matrix switch board 2 so as to connect the conductor patterns.
The connection pin insertion/extraction device shown in FIG. 1A and 1B is comprised of an optical sensor 4, a handling mechanism 5, an insertion-strength restriction mechanism 6 and a reversal mechanism 7.
The optical sensor 4, which is mounted on the handling mechanism 5, irradiates a laser beam from a laser port 4a onto a standard mark formed on the matrix switch board 2 and determines a positional relationship between the connection pin insertion/extraction device and the matrix switch board by detecting the strength of reflected laser light from the standard mark.
FIG. 2 is a diagram for explaining a detection method of the standard mark by the optical sensor 4. A standard mark 2a which has a high reflectivity is provided near a through-hole formed on the matrix switch board 2. In this case, the positional relationship between the through-hole and the standard mark 2a may be accurately determined by using the same patterning mask for the through-hole and the standard mark 2a.
The optical sensor 4 irradiates a laser beam onto a region of the standard mark 2a while moving in the directions indicated by the arrows in FIG. 2. At this time, the position of the standard mark 2a is determined by detecting the border lines between the standard mark 2a and the matrix switch board 2 from the strength of the reflected laser beam. Since the positional relationship between the standard mark 2a and the through-hole is accurately defined, the positional relationship between the through-hole and the robot may also be precisely determined.
As shown in FIG. 1A, the handling mechanism 5 is comprised of two rotary hooks 5a, a push rod 5b and an electromagnet 5c. The handling mechanism 5, which may be mounted on the insertion-strength restriction mechanism 6, carries out a holding/releasing operation of the connection pin 3. For example, the handling mechanism 5 with the rotary hooks 5a opened may be moved to the connection pin 3 and when it contacts the pin 3, the push rod 5b starts to move upward in the figure.
As the push rod 5b moves upward, a flange 5d which is formed on the push rod 5b closes the rotary hooks 5a, and at the same time, the push rod 5b contacts the electromagnet 5c. When the push rod 5b contacts the electromagnet 5c, the electromagnet is magnetized and the connection pin 3 is held by the rotary hooks 5a. Thus, the connection pin 3 may be extracted from the through-hole by moving the handling mechanism 5 in the upward direction.
The insertion-strength restriction mechanism 6 is operated so as to restrict the insertion strength of the connection pin 3 when the pin 3 is inserted in a through-hole. For instance, a certain force is required for inserting the connection pin 3 in the matrix switch board 2. However, the connection pin 3 may be damaged if too much force is applied to the pin 3. Therefore, a mechanism by which the insertion strength of the pin 3 may be restricted is necessarily provided with the connection pin insertion/extraction device.
The insertion-strength restriction mechanism 6, which is mounted between the handling mechanism 5 and the reversal mechanism 7, may be comprised of an insertion-strength generating spring 6a, a slider 6b, a rail 6c, a sensor 6d and a masking plate 6e. The rail 6c is fixed to the robot 1 via the reversal mechanism 7, and the handling mechanism 5 is mounted on a side surface of the slider 6b. The masking plate 6e is fixed on the upper surface of the slider 6b so that it may be moved with the slider 6b in the up and down directions. Also, the insertion-strength generating spring 6a, which is provided on the upper surface of the slider 6b, generates a stress (insertion strength) when the slider 6b moves in the up and down directions.
A light beam is ejected in the transverse direction in the sensor 6d. The sensor 6d determines a movement of the slider 6b when the slider 6b moves in the up or down direction and the masking plate 6e interrupts the light beam. That is, the sensor 6d detects that the insertion-strength generating spring 6a is contracted by a predetermined distance. The insertion-strength generating spring 6a is formed so that its insertion strength reaches a maximum limit when it is contracted by the predetermined distance in the above operation.
When the robot 1 is moved to a through-hole in order to insert the connection pin 3, the rail 6c and the slider 6b move in the downward direction in the figure. When the connection pin 3 starts to contact the through-hole, the insertion-strength generating spring 6a is deflected and generates an insertion force which is appropriate for inserting the connection pin 3 in the through-hole. After that, the robot 1 continues its movement and when the sensor 6d which is mounted on the rail 6c detects the masking plate 6e of the slider 6d, the insertion strength applied to the connection pin 3 reaches maximum and the insertion operation is terminated.
The reversal mechanism 7, which is provided between the insertion-strength restriction mechanism 6 and the robot 1, rotates the optical sensor 4, the handling mechanism 5 and the insertion-strength restriction mechanism 6 by 180 degrees so as to enable a both-side insertion/extraction of the connection pin 3.
However, according to the conventional connection pin insertion/extraction devices, the position of a through-hole is determined relative to the standard mark 2a on the matrix switch board, which is detected by the light beam. Thus, it is required to provide, additionally, the optical sensor 4 which optically detects the standard mark 2a with the connection pin insertion/extraction device. Also, it is necessary to additionally provide the reversal mechanism 7 with the connection pin insertion/extraction device in order to perform an insertion/extraction operation of the connection pin 3 for both sides of the matrix switch board.
Accordingly, it is not easy to reduce the size and the manufacturing cost of the conventional connection pin insertion/extraction device.
Moreover, in the conventional connection pin insertion/extraction device, since the optical sensor 4, which forms a position detection mechanism, is provided a certain distance away from the position of a connection pin, it is necessary to correct the position of a through-hole corresponding to the distance. This may become one of the error factors in the through-hole position detection operation and may cause an erroneous insertion of the connection pin.